Monitoring device for distributed antenna system

ABSTRACT

A monitoring device for a distributed antenna system including at least two node units communicatively coupled to each other transmits, to at least one target node unit among the node units, a data dump command for a first target signal passing through a first signal path in the target node unit. The monitoring device receives, from the target node unit, response data corresponding to the data dump command. The monitoring device generates first quality information indicative of the quality of the first target signal by using the response data.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. application Ser. No.15/084,603 filed Dec. 6, 2016, which is a Continuation of PCTInternational Application No. PCT/KR2015/014448, filed Dec. 29, 2015,and claims priority from Korean Patent Application Nos. 10-2014-0194367filed Dec. 30, 2014 and No. 10-2015-0026059 filed Feb. 24, 2015, thecontents of which are incorporated herein by reference in theirentireties.

BACKGROUND

1. Field

The inventive concept relates to a monitoring device applicable to adistributed antenna system (DAS).

2. Description of Related Art

Conventionally, there was used a method in which, when a service erroroccurred in a distributed antenna system (DAS) network, a managerdirectly checked whether a corresponding equipment was abnormal using aspectrum analyzer at a place where equipments constituting the DASnetwork were located.

However, the conventional method has the following problems when themanager monitors an error of the DAS network. For example, in the DASnetwork, a plurality of node units such as a head-end (HE) unit, aplurality of hub units, and a plurality of remote units arecommunicatively coupled to each other, and therefore, the manager hasdifficulty in detecting in which part a problem has occurred. Also, whenthe DAS network is applied to a subway, a relay tower, etc., a manager'saccess is limited, and therefore, the manager has difficulty in checkingwhether an error has occurred. Also, when a problem occurs in a servicedue to an error of a signal input from a base station, an abnormality ofan optical fiber, a defect of a remote unit, etc., the manager hasdifficulty in detecting an accurate cause. Also, when a service signalis degraded due to a defect of a power amplification unit (PAU), themanager has difficulty in detecting an accurate cause. Also, when aproblem occurs in a reverse service due to a defect of a specific remotenode, the manager has difficulty in detecting an abnormally operatingremote unit. Also, in the DAS network to which a direct digitalinterface (DDI) such as a common public radio interface/open basestation architecture initiative is applied, the manager cannot analyzethe occurrence cause, position, and the like of a failure by using theconventional method.

SUMMARY

An embodiment of the inventive concept is directed to a monitoringdevice applicable to a distributed antenna system (DAS).

According to an aspect of the inventive concept, there is a provided amonitoring device for a distributed antenna system including at leasttwo node units communicatively coupled to each other, the monitoringdevice: transmitting, to at least one target node unit among the nodeunits, a data dump command for a first target signal passing through afirst signal path in the target node unit; receiving, from the targetnode unit, response data corresponding to the data dump command; andgenerating first quality information indicative of the quality of thefirst target signal by using the response data.

According to an exemplary embodiment, wherein the response data may bedata stored in the target node unit while the first target signal isbeing processed by signal processing components related to the firstsignal path.

According to an exemplary embodiment, wherein the first qualityinformation may indicate a quality index for the first target signal,wherein the quality index may be related to at least one signal qualitycharacteristic among spectrum, power, peak level in time domain,adjacent channel leakage ratio (ACLR), error vector magnitude (EVM),occupied bandwidth (OBW), spectrum emission mask (SEM), noise figure(NF), complementary cumulative distribution function (CCDF), signal tonoise ratio (SNR), and spurious characteristic.

According to an exemplary embodiment, wherein the monitoring device maycomprise: an interface unit configured to transmit the data dump commandto the target node unit and receive the response data from the targetnode unit; a controller configured to generate the data dump command andgenerate the first quality information by using the response datatransmitted from the interface unit; and a display unit configured todisplay the first quality information.

According to an exemplary embodiment, wherein the controller may receivea manager's dump request input through a predetermined graphic userinterface (GUI) displayed on the display unit, generate the data dumpcommand in response to the manager's dump request input, and transmitsthe data dump command to the interface unit.

According to an exemplary embodiment, wherein the controller may receivea manager's information output request input through the predeterminedGUI displayed on the display unit, and transmit the first qualityinformation in response to the manager's information output requestinput.

According to an exemplary embodiment, wherein the monitoring device mayreceive, from the target node unit, report data on a second targetsignal passing through a second signal path in the target node unit, andgenerate second quality information indicative of the quality of thesecond target signal by using the report data.

According to an exemplary embodiment, wherein the report data may bedata stored in the target node unit while the second target signal isbeing processed by signal processing components related to the secondsignal path, and wherein the report data may be data transmitted fromthe target node unit regardless of the data dump command.

According to an exemplary embodiment, wherein the monitoring device mayanalyze whether a failure has occurred in the first signal path by usingthe response data, and generate first analysis information indicative ofwhether the failure has occurred in the first signal path, based on theanalyzed result.

According to an exemplary embodiment, wherein the monitoring device maydetect whether a failure has occurred in the first signal path by usingthe response data, and transmit, to the target node unit, apredetermined control signal for controlling the signal processingcomponents related to the first signal path, based on the detectedresult.

According to an exemplary embodiment, wherein the monitoring device maybe communicatively coupled to the target node unit through a wired orwireless network.

According to an exemplary embodiment, wherein the data dump command andthe response data may be transmitted through a control & management(C&M) channel or a specific channel between the monitoring device andthe target node unit.

According to another aspect of the inventive concept, there is aprovided a monitoring device for a distributed antenna system includingat least two node units communicatively coupled to each other, themonitoring device: receiving, from at least one target node unit amongthe node units, report data on a target signal passing through aspecific signal path in the target unit node; and generating qualityinformation indicative of the quality of the target signal by using thereport data.

According to an exemplary embodiment, wherein the report data may bedata stored in the target node unit while the target signal is beingprocessed by signal processing components related to the specific signalpath.

According to an exemplary embodiment, wherein the quality informationmay indicate a quality index for the target signal, wherein the qualityindex may be related to at least one signal quality characteristic amongspectrum, power, peak level in time domain, ACLR, EVM, OBW, SEM, NF,CCDF, SNR, and spurious characteristic.

According to an exemplary embodiment, wherein the monitoring device mayreceive, from the target node unit, self-analysis information indicativeof whether a failure has occurred in the specific signal path in thetarget node unit.

According to an exemplary embodiment, wherein the monitoring device maytransmit, the target node unit, a predetermined control signal forcontrolling the signal processing components related to the specificsignal path, based on the self-analysis information.

In the monitoring device for the DAS according to the inventive concept,a manager can monitor various failures that occur in a specific node ofthe DAS, further, internal signal processing components constituting thecorresponding specific node by remotely identifying the spectrum, errorvector magnitude (EVM), adjacent channel leakage ratio (ACLR), signal tonoise ratio (SNR), and the like of a specific signal path in the DASthrough a graphic user interface (GUI).

BRIEF DESCRIPTION OF THE FIGURES

Exemplary embodiments of the inventive concept will be more clearlyunderstood from the following detailed description taken in conjunctionwith the accompanying drawings in which:

FIG. 1 is a diagram illustrating an example of a topology of adistributed antenna system (DAS) as one form of a signal distributedtransmission system to which the inventive concept is applicable.

FIG. 2 is a block diagram illustrating an embodiment of a main unit inthe DAS to which the inventive concept is applicable.

FIG. 3 is a block diagram illustrating an embodiment of a hub unit inthe DAS to which the inventive concept is applicable.

FIG. 4 is a block diagram illustrating an embodiment of a remote unit inthe DAS to which the inventive concept is applicable.

FIG. 5 is a block diagram illustrating a monitoring device for the DASaccording to an embodiment of the inventive concept.

FIG. 6 is a diagram illustrating an operation of the monitoring devicefor the DAS according to the embodiment of the inventive concept.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Exemplary embodiments of the inventive concept will be described belowin more detail with reference to the accompanying drawings. Theinventive concept may, however, be embodied in different forms andshould not be construed as limited to the embodiments set forth herein.Rather, these embodiments are provided so that this disclosure will bethorough and complete, and will fully convey the scope of the inventiveconcept to those skilled in the art. Throughout the disclosure, likereference numerals refer to like parts throughout the various figuresand embodiments of the inventive concept.

In description of the inventive concept, detailed explanation of knownrelated functions and constitutions may be omitted to avoidunnecessarily obscuring the subject manner of the inventive concept.Ordinal numbers (e.g. first, second, etc.) are used for descriptiononly, assigned to the elements in no particular order, and shall by nomeans specify the name of the pertinent element or restrict the claims.

It will be understood that when an element is “connected” or “coupled”to another element, the element may be directly connected or coupled toanother element, and there may be an intervening element between theelement and another element. To the contrary, it will be understood thatwhen an element is “directly connected” or “directly coupled” to anotherelement, there is no intervening element between the element and anotherelement.

Hereinafter, a distributed antenna system (DAS) will be mainly describedas an application example to which embodiments of the inventive conceptare applicable. However, the embodiments of the inventive concept areidentically or similarly applicable to other signal distributedtransmission systems such as a base transceiver station distributedantenna system as well as the DAS.

FIG. 1 is a diagram illustrating an example of a topology of adistributed antenna system (DAS) as one form of a signal distributedtransmission system to which the inventive concept is applicable.

Referring to FIG. 1, the DAS 100 may include a base station interfaceunit (BIU) 10 and a main unit (MU) 20, which constitute a head-end node,a hub unit (HUB) 30 serving as an extension node, and a plurality ofremote units (RUs) 40 respectively disposed at remote service positions.The DAS 100 may be implemented as an analog DAS or a digital DAS. Whennecessary, the DAS 100 may be implemented as a hybrid of the analog DASand the digital DAS (e.g., to perform analog processing on some nodesand digital processing on the other nodes).

However, FIG. 1 illustrates an example of the topology of the DAS 100,and the DAS 100 may have various topologies in consideration ofparticularity of its installation areas and application fields (e.g.,in-building, subway, hospital, stadium, etc.). In view of the above, thenumber of the BIU 10, the MU 20, the HUB 30, and the RUs 40 andconnection relations between upper and lower nodes among the BIU 10, theMU 20, the HUB 30, and the RUs 40 may be different from those of FIG. 1.In the DAS 100, the HUB 30 may be used when the number of branches to bebranched in a star structure from the MU 20 is limited as compared withthe number of RUs 40 required to be installed. Therefore, the HUB 30 maybe omitted when only the single MU 20 sufficiently covers the number ofRUs 40 required to be installed, when a plurality of MUs 20 areinstalled, or the like.

Hereinafter, nodes in the DAS 100 applicable to the inventive conceptand their functions will be sequentially described based on the topologyof FIG. 1.

The BIU 10 serves as an interface between a base station transceiversystem (BTS) 5 and the MU 20. Although a case where three BTSs (BTS#1 toBTS#3) are connected to the single BIU 10 is illustrated in FIG. 1, theBIU 10 may be separately provided for each provider, each frequencyband, or each sector.

In general, a base station signal transmitted from the BTS 5 is a radiofrequency (RF) signal of high power. Hence, the BIU 10 may convert theRF signal of high power into a signal with power suitable to beprocessed in the MU 20 and transmit the converted signal to the MU 20.Also, the BIU 20, as shown in FIG. 1, may receive base station signalsfor each frequency band (or each provider or each sector), combine thereceived signals, and then transmit the combined signal to the MU 20.

When the BIU 10 converts RF signals of high power, transmitted from theBTS 5, into RF signals of low power, combines the RF signals, and thentransmits the combined RF signal to the MU 20, the MU 20 may distributethe combined and transmitted RF signal for each branch. In this case,when the DAS 100 is implemented as the digital DAS, the BIU 10 may beseparated into a unit for converting RF signals of high power into RFsignals of low power, and a unit for converting the RF signals of lowpower into intermediate frequency (IF) signals, processing the convertedIF signals into digital signals, and then combining the processeddigital signals. Alternatively, when the BIU 10 performs only thefunction of converting the RF signals of high power, transmitted fromthe BTS 5 into the RF signals of low power, the MU 20 may combine thetransmitted RF signals and distribute the combined RF signal for eachbranch.

As described above, the combined RF signal distributed from the MU 20may be transmitted to the RUs 40 through the HUB 30 or directlytransmitted to the RUs 40, for each branch (see Branch #1, . . . ,Branch #k, . . . , Branch #N of FIG. 1). Each RU 40 may separate thetransmitted combined RF signal for each frequency band and performsignal processing (analog signal processing in the analog DAS anddigital signal processing in the digital DAS). Accordingly, each RU 40can transmit RF signals to user terminals in its own service coveragethrough a service antenna. Specific components and functions of the RU40 will be described in detail below with reference to FIG. 4.

In FIG. 1, it is illustrated that the BTS 5 and the BIU 10 are connectedthrough an RF cable, the BIU 10 and the MU 20 are connected through anRF cable, and all nodes from the MU 20 to lower nodes thereof areconnected through optical cables. However, a signal transport mediumbetween nodes may be variously modified. As an example, the BIU 10 andthe MU 20 may be connected through an RF cable, but may be connectedthrough an optical cable or a digital interface. As another example, theMU 20 and HUB 30 may be connected through an optical cable, the MU 20and the RU 40 directly connected thereto may be connected through anoptical cable, and the cascade-connected RUs 40 may be connected throughan RF cable, a twist cable, a UTP cable, etc. As still another example,the MU 20 and the RU 40 directly connected thereto may also be connectedthrough an RF cable, a twist cable, a UTP cable, etc.

Hereinafter, this will be described based on FIG. 1. Therefore, in thisembodiment, each of the MU 20, the HUB 30, and the RUs 40 may include anoptical transceiver module for electrical-to-optical (E/O)conversion/optical-to-electrical (O/E) conversion. When node units areconnected through a single optical cable, each of the MU 20, the HUB 30,and the RUs 40 may include a wavelength division multiplexing (WDM)element.

The DAS 100 may be connected to an external monitoring device, i.e., anetwork management server or system 50 through a network. Hereinafter,the monitoring device 50 will be briefly referred to as NMS 50.Accordingly, a manager can remotely monitor states and problems of thenodes in the DAS 100 through the NMS 50, and can remotely controloperations of the nodes in the DAS 100 through the NMS 50.

FIG. 2 is a block diagram illustrating an embodiment of the MU in theDAS to which the inventive concept is applicable. Here, the blockdiagram of FIG. 2 illustrates an embodiment in which, as described withreference to FIG. 1, the MU 20 is connected to the BIU 10 through an RFcable and connected to the HUB 30 or the RU 40 through an optical cable.Also, the block diagram of FIG. 2 exemplarily illustrates onlycomponents related to a function of performing, by the MU 20, apredetermined signal processing on a signal transmitted from BIU 10through a downlink path and then transmitting the signal-processedsignal to the HUB 30 or the RU 40, and processing a signal received fromthe HUB 30 or the RU 40 through an uplink path.

Referring to FIG. 2, based on a downlink path (i.e., a forward path),the MU 20 may include a low noise amplifier 21 a, a down converter 22 a,an analog-to-digital (AD) converter 23 a, a digital signal processor 24,a framer 25 a, a serializer/deserializer (SERDES) 26, and anelectrical-to-optical (E/O) converter 27 a.

In the downlink path of the MU 20, an RF signal transmitted from the BIU10 (see FIG. 1) through an RF cable may be low-noise amplified by thelow noise amplifier 21 a and then frequency down-converted into anintermediate frequency (IF) signal by the down converter 22 a. Theconverted IF signal may be converted into a digital signal by the ADconverter 23 a to be transmitted to the digital signal processor 24. Thedigital signal processor 24 may perform a function of digital signalprocessing, digital filtering, gain control, digital multiplexing, etc.on a digitized RF signal for each frequency band. The digitized RFsignal passing through the digital signal processor 24 may be formattedin a format suitable for digital transmission through the framer 25 a,converted into a serial digital signal by the SERDES 26, converted intoan optical digital signal by the E/O converter 27 a, and thentransmitted to a lower node unit, e.g., the HUB 30 (see FIG. 1) or theRU 40 (see FIG. 1) through an optical cable.

Based on an uplink path (i.e., a reverse path), the MU 20 may include anoptical-to-electrical (O/E) converter 27 b, the SERDES 26, a deframer 25b, the digital signal processor 24, a digital-to-analog (DA) converter23 b, an up converter 22 b, and a power amplifier 21 b.

In the uplink path of the MU 20, an optical digital signal transmittedfrom a lower node unit through an optical cable may be converted into anelectrical signal (serial digital signal) by the O/E converter 27 b. Theserial digital signal may be converted into a parallel digital signal bythe SERDES 26. The parallel digital signal may be reformatted by thedeframer 25 b to be processed for each frequency band in the digitalsignal processor 24. The digital signal passing through the digitalsignal processor 24 may be converted into an analog signal through theDA converter 23 b. Here, the analog signal is an IF signal, and hencemay be frequency up-converted into an analog signal in the original RFband through the up converter 22 b. The analog signal (i.e., the RFsignal) converted into the analog signal in the original RF band isamplified through the power amplifier 21 b and then transmitted to theBIU 10 through an RF cable.

In FIG. 2, the digital signal processor 24, the framer 25 a, thedeframer 25 b, and the SERDES 26 may constitute a digital part MDP, andat least two of the digital signal processor 24, the framer 25 a, thedeframer 25 b, and the SERDES 26 may be implemented as one fieldprogrammable gate array (FPGA). In addition, an MU controller 28 whichwill be described later may also be implemented, as the FPGA, togetherwith the at least two of the digital signal processor 24, the framer 25a, the deframer 25 b, and the SERDES 26. Although it is illustrated thatthe digital signal processor 24 and the SERDES 26 are commonly used ineach of the downlink and uplink paths, the digital signal processor 24and the SERDES 26 may be separately provided for each path.

In FIG. 2, at least two of the low noise amplifier 21 a, the downconverter 22 a, and the AD converter 23 a in the downlink path and theDA converter 23 b, the up converter 22 b and the power amplifier 21 b inthe uplink path may be implemented as one chip, e.g., a radio frequencyintegrated circuit (RFIC).

In FIG. 2, the E/O converter 27 a and the O/E converter 27 b mayconstitute an optical part MOP. Although it is illustrated that thecorresponding E/O and O/E converters are provided in the downlink anduplink paths, respectively, the E/O and O/E converters may beimplemented as a single optical transceiver module (e.g., a signal smallform factor pluggable (SFP)).

In FIG. 2, it is illustrated that the power amplifier 21 b and the upconverter 22 b are included in the MU 20. However, when the BIU 10, asdescribed with reference with reference to FIG. 1, includes a unit forconverting signals of high power into signals of low power or a unit forconverting signals of low power into IF signals, processing theconverted IF signals into digital signals, and then combining theprocessed digital signals, the power amplifier 21 b and/or the upconverter 22 b may be omitted. Similarly, the low noise amplifier 21 aand/or the down converter 22 a may also be omitted in the MU 20,corresponding to components of the BIU 20.

Meanwhile, although not mentioned in the description related to thedownlink and uplink paths, the MU 20 may further include an MUcontroller 28.

The MU controller 28 may be configured to transmit/receive signalsto/from at least one of the digital signal processor 24, the framer 25a, the deframer 25 b, and the SERDES 26, which constitute the digitalpart MDP.

The MU controller 28 may control the components in the digital part MDPof the MU 20 to perform a required signal processing operation. Forexample, the MU controller 28 may control the digital signal processor24, the framer 25 a, the deframer 25 b, the SERDES 26, and the like,corresponding to a kind of signal transmitted between upper nodes and/orlower nodes, a required quality, etc. Specifically, the MU controller 28may determine a kind of signal such as CDMA, WCDMA, LTE, or WiBrosignal, transmitted from BTS 5 or the RU 40, and may control thecomponents in the digital part MDP, corresponding to the determinedkind.

However, this is merely illustrative, and it will be apparent that theMU controller 28 may be configured to transmit/receive signals to/fromother components in the MU 20 as well as the digital part MDP, and maycontrol the other components.

The MU controller 28 may receive signals for controlling the componentsin the MU 20 from the NMS 50 (see FIG. 1) connected through a wired orwireless network. Alternatively, the MU controller 28 may receivesignals for controlling the components in the MU 20 through a lower nodeunit (the HUB 30 or the RU 40) (see FIG. 1). Alternatively, the MUcontroller 28 may receive, from the NMS 50, signals for controlling thecomponents in the lower node unit, and may transmit the received signalsto the corresponding node unit. Here, the signals for controlling thecomponents in the lower node unit may be processed together with basestation signals or separately processed by the digital part MDP to betransmitted to the other lower node units. Hereinafter, when controlsignals, commands, data, etc. are transmitted between node units, theyare processed together with base station signals or separately processedby a digital part of one node unit to be transmitted to the other nodeunits, and therefore, overlapping descriptions will be omitted.

The MU controller 28 may dump, into a predetermined storage area (e.g.,a ROM, a RAM, etc.), data corresponding to signals processed in thedigital signal processor 24, the framer 25 a, the deframer 25 b, theSERDES 26, and the like.

In an embodiment, the MU controller 28 may receive a data dump commanddirectly transmitted from the NMS 50 or transmitted from the lower nodeunit, and may dump the data into the storage area in response to thedata dump command. The MU controller 28 may directly transmit the dumpeddata as response data to the NMS 50 or transmit the dumped data to theNMS 50 through the lower node unit. However, the inventive concept isnot limited thereto, and it will be apparent that the MU controller 28may perform a predetermined processing process on the dumped data andthen directly transmit the dumped data as the response data to the NMS50 or transmit the dumped data to the NMS 50 through the lower nodeunit.

In another embodiment, the MU controller 28 may dump the data for apredetermined period regardless of the data dump command, and maydirectly transmit the dumped data as report data to the NMS 50 ortransmit the dumped data to the NMS 50 through the lower node unit.However, the inventive concept is not limited thereto, and it will beapparent that the MU controller 28 may perform a predeterminedprocessing process on the dumped data and then directly transmit thedumped data as the report data to the NMS 50 or transmit the dumped datato the NMS 50 through the lower node unit.

Accordingly, the NMS 50 can generate predetermined informationrepresenting the quality of a signal, the occurrence of a failure, etc.on a specific signal path in the MU 20 and provide a manager with thegenerated information. When a failure occurs, the manager enables theNMS 50 to take action against the failure, or the NMS 50 can directlytake action against the failure. This will be described in detail withreference to FIGS. 5 and 6.

Meanwhile, according to an embodiment, the MU controller 28 may detectthe occurrence of an failure by analyzing the quality of a signal on aspecific signal path, based on the response data or the report data, andmay generate self-analysis information representing the occurrence ofthe failure on the specific signal path, based on the detected result.The MU controller 28 may transmit the generated self-analysisinformation to the NMS 50. Alternatively, the MU controller 28 may takeaction against the failure by controlling components related to thespecific signal path on which the failure occurs, based on the generatedself-analysis information.

FIG. 3 is a block diagram illustrating an embodiment of the HUB in theDAS to which the inventive concept is applicable.

Referring to FIG. 3, based on a downlink path, the HUB 30 may include anO/E converter 31 a, a digital signal processor 33, and E/O converters 35a and 37 a.

In the downlink path of the HUB 30, an optical digital signaltransmitted from the MU through an optical cable may be converted intoan electrical signal by the O/E converter 31 a. The digital signalprocessor 33 may perform predetermined signal processing on theconverted electrical signal and distribute the converted electricalsignal to the plurality of E/O converters 35 a and 37 a. Each of the E/Oconverters 35 a and 37 a may receive the distributed signal to convertthe electrical signal into an optical digital signal and transmit theconverted optical digital signal to the lower RU 40. Although only twoE/O converters 35 a and 37 a are illustrated in FIG. 3 for convenienceof illustration, the E/O converter may be provided in pluralitycorresponding to the number of RU 40 (see FIG. 1) connected as lowernode units to the HUB 30.

Based on an uplink path, the HUB 30 may include O/E converters 35 b and37 b, the digital signal processor 33, and an E/O converter 31 b.

An optical digital signal transmitted from the RU 40 through an opticalcable may be converted into electrical signals by the O/E converters 35b and 37 b. The digital signal processor 33 may combine the plurality ofconverted electrical signals and transmit the combined electrical signalto the E/O converter 31 b. The E/O converter 31 b may convert thecombined electrical signal into an optical digital signal and transmitthe converted optical digital signal to the upper MU 20 (see FIG. 1).

In FIG. 3, it is illustrated that corresponding O/E and E/O convertersare separately provided for each of optical parts HOP1, HOP2, and HOP3.However, as described with reference to FIG. 2, each of the opticalparts HOP1, HOP2, and HOP3 may be configured as a single opticaltransceiver module.

Meanwhile, although not mentioned in the description related to thedownlink and uplink paths, the HUB 30 may further include a HUBcontroller 39.

The HUB controller 39 may be configured to transmit/receive signalsto/from the digital signal processor 33, and may control the componentsin the digital signal processor 33 to perform a required signalprocessing operation. However, this is merely illustrative, and it willbe apparent that the HUB controller 39 may be configured totransmit/receive signals to/from other components in the HUB 30 as wellas the digital signal processor 33, and may control the othercomponents.

The HUB controller 39 may receive signals for controlling the componentsin the HUB 30 from the NMS 50 (see FIG. 1) connected through the wiredor wireless network. Alternatively, the HUB controller 39 may receivesignals for controlling the components in the HUB 30 through an adjacentnode unit (the MU 20 or the RU 40) (see FIG. 1). The HUB controller 39may receive, from the NMS 50, signals for controlling the components inthe adjacent node unit, and may transmit the received signals to thecorresponding node unit.

The HUB controller 39 may dump, into a predetermined storage area (e.g.,a ROM, a RAM, etc.), data corresponding to signals processed in thedigital signal processor 33.

In an embodiment, the HUB controller 39 may receive a data dump commandthat is directly transmitted from the NMS 50 (see FIG. 1) connectedthrough the wired or wireless network or transmitted from the adjacentnode unit. The HUB controller 39 may dump the data into the storage areain response to the data dump command. The HUB controller 39 may directlytransmit the dumped data as response data to the NMS 50 or transmit thedumped data to the NMS 50 through the adjacent node unit. However, theinventive concept is not limited thereto, and it will be apparent thatthe HUB controller 39 may perform a predetermined processing process onthe dumped data and then directly transmit the dumped data as theresponse data to the NMS 50 or transmit the dumped data to the NMS 50through the adjacent node unit.

In another embodiment, the HUB controller 39 may dump the data for apredetermined period regardless of the data dump command, and maydirectly transmit the dumped data as report data to the NMS 50 ortransmit the dumped data to the NMS 50 through the adjacent node unit.However, the inventive concept is not limited thereto, and it will beapparent that the HUB controller 39 may perform a predeterminedprocessing process on the dumped data and then directly transmit thedumped data as the report data to the NMS 50 or transmit the dumped datato the NMS 50 through the adjacent node unit.

Accordingly, the NMS 50 can generate predetermined informationrepresenting the quality of a signal, the occurrence of a failure, etc.on a specific signal path in the HUB 30 and provide a manager with thegenerated information. When a failure occurs, the manager enables theNMS 50 to take action against the failure, or the NMS 50 can directlytake action against the failure.

Meanwhile, according to an embodiment, the HUB controller 39 may detectthe occurrence of a failure by analyzing the quality of a signal on aspecific signal path, based on the response data or the report data, andmay generate self-analysis information representing the occurrence ofthe failure on the specific signal path, based on the detected result.The HUB controller 39 may transmit the generated self-analysisinformation to the NMS 50. Alternatively, the HUB controller 39 may takeaction against the failure by controlling components related to thespecific signal path on which the failure occurs, based on the generatedself-analysis information.

FIG. 4 is a block diagram illustrating an embodiment of the RU in theDAS to which the inventive concept is applicable.

Here, the block diagram of FIG. 4 illustrates an embodiment related tothe RU 40 in the digital DAS in which node units are connected throughan optical cable. Also, the block diagram of FIG. 4 illustrates onlycomponents related to a function of providing terminal in servicecoverage with signals from an upper node unit through a downlink pathand processing terminal signals received from the terminals in theservice coverage through an uplink path.

Referring to FIG. 4, based on a downlink path, the RU 40 may include anO/E converter 41 a, a SERDES 42, a deframer 43 a, a digital signalprocessor 44, a DA converter 45 a, an up converter 46 a, and a poweramplifier 47 a.

In the downlink path of RU 40, an optical digital signal transmittedfrom an upper node unit (the MU 20 or the HUB 30) (see FIG. 1) throughan optical cable may be converted into an electrical signal (serialdigital signal) by the O/E converter 41 a. The serial digital signal maybe converted into a parallel digital signal by the SERDES 42. Theparallel digital signal may be reformatted by the deframer 43 a to beprocessed for each frequency band in the digital signal processor 44.The digital signal processor 44 may perform a function of digital signalprocessing, digital filtering, gain control, digital multiplexing, etc.on the reformatted digital signal for each frequency band. The digitalsignal passing through the digital signal processor 44 may be convertedinto an analog signal through the DA converter 45 a. Here, the analogsignal is an IF signal, and hence may be frequency up-converted into ananalog signal in the original RF band through the up converter 46 a. Theanalog signal (i.e., the RF signal) converted into the analog signal inthe original RF band may be amplified through the power amplifier 47 ato transmitted through a service antenna (not shown).

Based on an uplink path, the RU 40 may include a low noise amplifier 47b, a down converter 46 b, an AD converter 45 b, the digital signalprocessor 44, a framer 43 b, the SERDES 42, and an E/O converter 41 b.

In the uplink path of the RU 40, an RF signal (i.e., a terminal signal)received through the service antenna (not shown) from a user terminal(not shown) in a service coverage may be low-noise amplified by the lownoise amplifier 47 b and frequency down-converted into an IF signal bythe down converter 46 b. The converted IF signal may be converted into adigital signal by the AD converter 45 b to be transmitted to the digitalsignal processor 44. The digital signal passing through the digitalsignal processor 44 may be formatted in a format suitable for digitaltransmission through the framer 43 b and converted into a serial digitalsignal by the SERDES 42. The serial digital signal may be converted intoan optical digital signal by the E/O converter 41 b to be transmitted toan upper node unit through an optical cable.

Although not clearly shown in FIG. 4, the following method may be usedwhen a signal transmitted from an upper node unit is transmitted to alower adjacent RU cascade-connected to the upper node unit in a state inwhich the RUs 40 are cascade-connected to each other as illustrated inFIG. 1. For example, when an optical digital signal transmitted from anupper node unit is transmitted to a lower adjacent RU cascade-connectedto the upper node unit, the optical digital signal transmitted from theupper node unit may be transmitted to the lower adjacent RU sequentiallythrough the O/E converter, the SERDES, the deframer, the framer, theSERDES, and the E/O converter.

As described with reference to FIG. 4, the SERDES 42, the deframer 43 a,the framer 43 b, and the digital signal processor 44 in the RU 40 mayconstitute a digital part RDP, and at least two of the SERDES 42, thedeframer 43 a, the framer 43 b, and the digital signal processor 44 maybe implemented as one FPGA. In addition, an RU controller 48 which willbe described later may also be implemented, as the FPGA, together withthe at least two of the SERDES 42, the deframer 43 a, the framer 43 b,and the digital signal processor 44. Although it is illustrated in FIG.4 that the SERDES 42 and the digital signal processor 44 are commonlyused in each of the downlink and uplink paths, the SERDES 42 and thedigital signal processor 44 may be separately provided for each path.

In FIG. 4, at least two of the DA converter 45 a, the up converter 46 a,and the power amplifier 47 a in the downlink path and the low noiseamplifier 47 b, the down converter 46 b, and the AD converter 45 b inthe uplink path may be implemented as one chip, e.g., one RFIC.

In FIG. 4, the O/E converter 41 a and the E/O converter 41 b mayconstitute an optical part ROP. Although it is illustrated that thecorresponding E/O and O/E converters are provided in the downlink anduplink paths, respectively, the E/O and O/E converters may beimplemented as a single optical transceiver module.

Meanwhile, although not mentioned in the description related to thedownlink and uplink paths, the RU 40 may further include an RUcontroller 48.

The RU controller 48 may be configured to transmit/receive signalsto/from at least one of the SERDES 42, the deframer 43 a, the framer 43b, and the digital signal processor 44, which constitute a digital partRDP. The RU controller 48 may control the components in the digital partRDP to perform a required signal processing operation. However, this ismerely illustrative, and it will be apparent that the RU controller 48may be configured to transmit/receive signals to/from other componentsin the RU 20 as well as the digital part RDP, and may control the othercomponents.

The RU controller 48 may receive signals for controlling the componentsin the RU 40 from the NMS 50 (see FIG. 1) connected through the wired orwireless network. Alternatively, the RU controller 48 may receivesignals for controlling the components in the RU 40 through an uppernode unit (the MU 20 or the HUB 30) (see FIG. 1). The RU controller 48may receive, from the NMS 50, signals for controlling the components inthe upper node unit, and may transmit the received signals to thecorresponding node unit.

The RU controller 48 may dump, into a predetermined storage area (e.g.,a ROM, a RAM, etc.), data corresponding to signals processed in theSERDES 42, the deframer 43 a, the framer 43 b, the digital signalprocessor 44, etc.

In an embodiment, the RU controller 48 may receive a data dump commandthat is directly transmitted from the NMS 50 or transmitted from theupper node unit. The RU controller 48 may dump the data into the storagearea in response to the data dump command. The RU controller 48 maydirectly transmit the dumped data as response data to the NMS 50 ortransmit the dumped data to the NMS 50 through the upper node unit.However, the inventive concept is not limited thereto, and it will beapparent that the RU controller 48 may perform a predeterminedprocessing process on the dumped data and then directly transmit thedumped data as the response data to the NMS 50 or transmit the dumpeddata to the NMS 50 through the upper node unit.

In another embodiment, the RU controller 48 may dump the data for apredetermined period regardless of the data dump command, and maydirectly transmit the dumped data as report data to the NMS 50 ortransmit the dumped data to the NMS 50 through the upper node unit.However, the inventive concept is not limited thereto, and it will beapparent that the RU controller 48 may perform a predeterminedprocessing process on the dumped data and then directly transmit thedumped data as the report data to the NMS 50 or transmit the dumped datato the NMS 50 through the upper node unit.

Accordingly, the NMS 50 can generate predetermined informationrepresenting the quality of a signal, the occurrence of a failure, etc.on a specific signal path in the RU 40 and provide a manager with thegenerated information. When a failure occurs, the manager enables theNMS 50 to take action against the failure, or the NMS 50 can directlytake action against the failure. This will be described in detail withreference to FIGS. 5 and 6.

Meanwhile, according to an embodiment, the RU controller 48 may detectthe occurrence of a failure by analyzing the quality of a signal on aspecific signal path, based on the response data or the report data, andmay generate self-analysis information representing the occurrence ofthe failure on the specific signal path, based on the detected result.The RU controller 48 may transmit the generated self-analysisinformation to the NMS 50. Alternatively, the RU controller 48 may takeaction against the failure by controlling components related to thespecific signal path on which the failure occurs, based on the generatedself-analysis information.

In the above, a configuration example of one form of the topology of theDAS, the MU 20, the HUB 30, and the RU 40 has been described withreference to FIGS. 1 to 4. However, the configuration example of FIGS. 1to 4 is merely one embodiment, and it will be apparent that variousapplication examples may be considered.

FIG. 5 is a block diagram illustrating a monitoring device for the DASaccording to an embodiment of the inventive concept. The monitoringdevice 50, i.e., the NMS 50, as shown in FIG. 1, may be communicativelycoupled to node units constituting the DAS 100. The NMS 50 enables amanager to monitor the quality of signals passing through various pathsin a target node unit to be monitored among the node units by using datarelated to signal processing, transmitted from the target node unit.Also, the NMS 50 detects a failure of the target node unit or a nodeunit adjacent to the target node unit, to enable the manager to identifythe detected failure or to directly take action against the detectedfailure.

Referring to FIG. 5, the NMS 50 may include an interface unit 51, acontroller 53, a display unit 55, and a storage unit 57.

First, the controller 53 may control overall operations of the NMS 50.The controller 53 may generate various commands and control signals forcontrolling a target node unit. The controller 53 may generatepredetermined information by using response data and report data,transmitted from the target node unit.

For example, the controller 53 may generate a data dump command for atarget signal passing through a specific signal path of the target nodeunit. The controller 53 may receive a manager's dump request inputthrough a predetermined graphic user interface (GUI) displayed on thedisplay unit 55, and may generate the data dump command in response tothe manager's dump request input.

The controller 53 may transmit the data dump command to the interfaceunit 51 such that the data dump command is transmitted to the targetnode unit. The target node unit may dump data stored therein while thetarget signal is being processed through a signal processingconfiguration related to the specific signal path in response to thedata dump command, and may transmit the dumped data as response data tothe NMS 50.

The controller 53 may receive the response data through the interfaceunit 51, and may generate quality information by using the responsedata. For example, the quality information may represent a quality indexrelated to characteristics of the target signal, such as spectrum,power, peak level in time domain, adjacent channel leakage ratio (ACLR),error vector magnitude (EVM), occupied bandwidth (OBW), spectrumemission mask (SEM), noise figure (NF), complementary cumulativedistribution function (CCDF), signal to noise ratio (SNR), and spuriouscharacteristic. However, the inventive concept is not limited thereto,and it will be apparent that the quality information may represent aquality index related to characteristics of various other signals.

The controller 53 may receive a manager's information output requestinput through the predetermined GUI displayed on the display unit 55.The controller 53 may transmit the quality information to the displayunit 55 in response to the manager's information output request input.Accordingly, the display unit 55 can display the quality information,and the manager can detect the occurrence of an failure by monitoring aquality status of signals in a specific signal path of the target nodeunit.

Meanwhile, the target node unit may dump data stored therein while thetarget signal is being processed through a signal processingconfiguration related to the specific signal path regardless of the datadump command, and may transmit the dumped data as response data to theNMS 50. Here, self-data dump of the target node unit may be performedfor a predetermined period.

In this case, the controller 53 may receive the report data through theinterface unit 51, and may generate quality information by using thereport data. Also, the controller 53 may transmit quality information tothe display unit 55 in response to a manager's information outputrequest through the GUI. Alternatively, the controller 53 mayarbitrarily transmit quality information to the display unit 55.Accordingly, the display unit 55 can display the quality information,and the manager can detect the occurrence of a failure by monitoring aquality status of signals in a specific signal path of the target nodeunit.

According to an embodiment, the controller 53 may analyze whether anfailure has occurred in a signal path of a corresponding target node,based on response data or report data, and may generate analysisinformation representing whether a failure has occurred in thecorresponding signal path, based on the analyzed result. The controller53 may analyze whether a failure has occurred from the response data orthe report data according to a previously set algorithm. The analysisinformation may further include information on a component (node unit)related to the failure, information related to a cause of the failure,etc. The controller 53 may transmit the analysis information to thedisplay unit 55 in response to a manager's request through the GUI.Alternatively, the controller 53 may arbitrarily transmit the analysisinformation to the display unit 55. Accordingly, the display unit 55 candisplay the analysis information, and the manager can identify whether afailure has occurred in the specific signal path of the target nodeunit, to take action against the failure.

The controller 53 may receive, from a target node, self-analysisinformation generated as the corresponding target node analyzes whetheran failure has occurred in a specific signal path. The self-analysisinformation may further include information on a component (node unit)related to the failure, information related to a cause of the failure,etc. It will be apparent that the controller 53 may display theself-analysis information on the display unit 55 in response to amanager's request through the GUI or may arbitrarily display theself-analysis information on the display unit 55.

According to another embodiment, the controller 53 may detect whether afailure has occurred in a signal path of a corresponding target node,based on response data or report data. The controller 53 may generate apredetermined control signal for controlling the target node unit inwhich the failure has directly occurred or another node unit, based onthe detected result. For example, when the target node unit is an RU,and it is detected that a failure has occurred in a component on anuplink path of the corresponding RU, the controller 53 may generate asignal for controlling a HUB, an MU, etc. as an upper node of thecorresponding RU not to sum up a signal transmitted from thecorresponding RU to signals transmitted from other RUs. The controller53 may transmit the generated control signal to the target node in whichthe failure has occurred or another node unit through the interface unit51, to rapidly take action against the failure.

Meanwhile, the controller 53 may generate a predetermined control signalfor controlling the target node unit in which the failure has occurredor another node unit, based on self-analysis information transmittedfrom the target node, to take action against the failure.

The controller 53 may transmit, to the storage unit 57, at least one ofthe response data, the report data, the quality information, theanalysis information, and the self-analysis information. The controller53 may transmit data and information to the storage unit 57 at apreviously set time interval for only a specific time. Alternatively,the controller 53 may transmit related information to the storage unit57 only when a failure is detected. Meanwhile, kinds and conditions ofthe data and the information to be stored in the storage unit 57 may beset in response to a manager's input through a predetermined GUI.

The interface unit 51 may transmit/receive a data dump command, responsedata, report data, etc. to/from the target node unit through a wired orwireless network. The data dump command, the response data, the reportdata, etc. may be transmitted through a control & management (C&M)channel between the interface unit 51 and the target node. For example,the C&M channel may be a channel except a payload through whichprocessing and/or processed data is transmitted, and may use a protocolsuch as Ethernet. However, the inventive concept is not limited thereto,and the data dump command, the response data, the report data, etc. maybe transmitted through a different channel from the C&M channel. Forexample, the data dump command, the response data, the report data, etc.may be transmitted through a specific channel between the interface unit51 and the target node unit. For example, like a channel fortransmission/reception of a delay measurement pulse, the specificchannel may be a channel separately assigned between the interface unit51 and the target node unit so as to transmit/receive the data dumpcommand, the response data, the report data, etc.

The display unit 55 may be a display device for displaying predeterminedGUIs. The storage unit 57 may be a storage device for storing responsedata, report data, quality information, analysis information, etc.

FIG. 6 is a diagram illustrating an operation of the monitoring devicefor the DAS according to the embodiment of the inventive concept. InFIG. 6, for convenience of illustration, the HUB 30 is omitted, and onlythe BTS 5, the BIU 10, the MU 20, the RU 40, and the NMS 50 areillustrated. Also, for convenience in description that target nodes arethe MU 20 and the RU 40, only the digital parts MDP and RDP respectivelycorresponding to the MU 20 and the RU 40 are illustrated in FIG. 6.Hereinafter, an operation of the NMS 50 will be described with referenceto FIG. 6 together with FIG. 5.

A case where a target node is the MU 20 will be described with referenceto FIGS. 5 and 6. The controller 53 of the NMS 50 transmits, to the MUcontroller 28, a data dump command for a target signal passing through aspecific signal path of the MU controller 28 through the interface unit51 in response to a manager's request, and the MU controller 28transmits response data on the target signal to the NMS 50 by performinga data dump.

As an example of the specific signal path detected in FIG. 6,input/output terminals of the digital signal processor 24 arerepresented by dotted-line circles. That is, path P1 and path P2 in thedownlink path and path P3 and path P4 in the uplink path are illustratedbased on the digital signal processor 24 of the MU 20.

When the manager intends to identify signal quality and/or detect theoccurrence of an failure in the path P1, the controller 53 transmits, tothe MU controller 28, a data dump command for a target signal passingthrough the path P1 through the interface unit 51. The MU controller 28transmits, to the controller 53, response data corresponding to thetarget signal passing through the path P1 from the digital signalprocessor 24 in response to the data dump command.

The controller 53 may generate quality information representing thequality of the target signal by using the response data and transmit thegenerated quality information to the display unit 55. Alternatively, thecontroller 53 may generate analysis information representing whether afailure has directly occurred in the path P1, a cause of the failure,etc. by using the response data. Here, it can be determined whichcomponent and which node unit the failure in the path P1 results from,based on address information included in the response data. That is,components related to a specific path of a specific node and addressinformation on node units are included response data corresponding tothe data dump command.

In FIG. 6, when it is detected by the NMS 50 that a failure has occurredin the path P1 due to abnormality of the quality of a signal passingthrough the path P1, e.g., a signal transmitted from the BIU 10, themanager may determine the failure as a defect of the BIU 10 or a defectof the base station, i.e., the BTS 5. If the BIU 10 is omitted, themanager may determine the failure as a defect of the BTS 5. Meanwhile,according to an embodiment, the BIU 10 may be monitored by the NMSsimilarly to other node units. In this case, the manager may detect aspecific cause of the occurrence of the failure by additionallyrequesting a data dump command for input and output paths of the BIU 10through the NMS 50. For example, when the quality of a signal passingthrough the input path of the BIU 10 is abnormal, the manager maydetermine the abnormality as a defect of the BTS 5. When the quality ofa signal passing through the output path of the BIU 10 is abnormal, themanager may determine the abnormality as a defect of the BIU 10. Thus, aspecific cause of the occurrence of a failure can be detected.

Similarly, the NMS 50 may generate quality information and analysisinformation, based on response data by performing a data dump on each ofthe paths P2 to P4, corresponding to a manager's input. The manager maydetect a cause of the occurrence of a failure in each of the paths P2 toP4, based on the quality information and the analysis information, totake action against the failure.

For example, when it is detected by the NMS 50 that a failure hasoccurred in the path P2 due to abnormality of the quality of a signalpassing through the path P2, the manager may determine the failure as adefect of the digital signal processor 24, a defect of the BIU 10, adefect of a component (e.g., the AD converter 23 a (see FIG. 2), etc.)prior to the digital part MDP on the downlink path. In order to morespecifically analyze a cause of the occurrence of the failure, qualityinformation and analysis information on the path P2 may be used togetherwith the quality information and analysis information on the path P1.

Similarly to the monitoring method of the MU 20, the NMS 50 may requesta data dump to be performed on each of paths P4 to P8 in response of amanager's input, and may receive response data transmitted from the RUcontroller 48 of the RU 40 in response to the data dump. The NMS 50 maygenerate quality information and analysis information, based on theresponse data transmitted from the RU 40. Accordingly, the manager candetect a cause of the occurrence of a failure in each of the paths P4 toP8, to take action against the failure.

For example, when it is detected by the NMS 50 that a failure hasoccurred in the path P8 due to abnormality of the quality of a signalpassing through the path P8, the manager may determine the failure as adefect of a component posterior to the digital part on the uplink path,e.g., the AD converter 45 b, the service antenna of the RU 40, a lowerRU, etc. Meanwhile, in order to respond a manager's input or preventdegradation of the DAS 100, the NMS 50 may generate a signal forcontrolling the digital signal processor 24 such that the upper MU 20does not sum up a reverse signal of the RU 40 in which the failure hasoccurred to signals transmitted from other RUs, and may transmit thegenerated signal to the MU controller 28 of the MU 20.

Meanwhile, similarly to the method of monitoring the target node unit byusing the response data received in response to the data dump command,the NMS 50 may generate predetermined information such that the managercan monitor the quality of a signal passing through a specific signalpath in the MU 20 or the RU 40 and the occurrence of a failure, based onreport data transmitted from the MU 20 or the RU 40. Further, the NMS 50may generate a signal for controlling a node unit in which a failure hasoccurred to be transmitted to the corresponding node unit.

Although the inventive concept has been described in connection with theexemplary embodiments, the inventive concept is not limited thereto butdefined by the appended claims. Accordingly, it will be understood bythose skilled in the art that various modifications and changes can bemade thereto without departing from the spirit and scope of theinventive concept defined by the appended claims.

What is claimed is:
 1. A monitoring device for a distributed antennasystem, the monitoring device comprising: a controller configured togenerate a dump command for a first signal passing through a first pathin a digital part of at least one node unit of the distributed antennasystem; and an interface unit configured to transmit the dump command tothe node unit through a network and receive response data from the nodeunit through the network, wherein the controller is further configuredto generate first quality information for the first signal based on theresponse data, and wherein the node unit is configured to, in responseto the dump command, store first data related to the first signal beingprocessed by at least one signal processing component on the first pathand transmit the first data to the monitoring device as the responsedata through the network.
 2. The monitoring device of claim 1, whereinthe first quality information includes a quality index for the firstsignal, wherein the quality index is related to at least one signalquality characteristic among spectrum, power, peak level in time domain,adjacent channel leakage ratio (ACLR), error vector magnitude (EVM),occupied bandwidth (OBW), spectrum emission mask (SEM), noise figure(NF), complementary cumulative distribution function (CCDF), signal tonoise ratio (SNR), and spurious characteristic.
 3. The monitoring deviceof claim 1, wherein the monitoring device further comprises a displayunit configured to display the first quality information.
 4. Themonitoring device of claim 3, wherein the controller is furtherconfigured to receive a dump request input through a predeterminedgraphic user interface (GUI) displayed on the display unit and generatethe dump command in response to the dump request input.
 5. Themonitoring device of claim 3, wherein the controller is furtherconfigured to receive an information output request input through apredetermined GUI displayed on the display unit and transmit the firstquality information to the display unit in response to the informationoutput request input.
 6. The monitoring device of claim 1, wherein theinterface unit is further configured to receive, from the node unit,report data on a second signal passing through a second path in thedigital part of the node unit through the network, and wherein thecontroller further configured to generate second quality information forthe second signal by using the report data.
 7. The monitoring device ofclaim 6, wherein the node unit is further configured to, at apredetermined period regardless of the dump command, store second datarelated to the second signal being processed by at least one signalprocessing component on the second path and transmit the second data tothe monitoring device as the report data through the network.
 8. Themonitoring device of claim 1, wherein the controller is furtherconfigured to analyze whether a failure has occurred in the first pathbased on the response data, and generate first analysis informationbased on a result of the analysis.
 9. The monitoring device of claim 1,wherein the controller is further configured to detect whether a failurehas occurred in the first path based on the response data and generate acontrol signal for controlling the signal processing component based ona result of the detection, and wherein the interface unit is furtherconfigured to transmit the control signal to the node unit through thenetwork.
 10. The monitoring device of claim 1, wherein the dump commandand the response data are transmitted between the monitoring device andthe node unit through a control & management (C&M) channel of thenetwork or a specific channel of the network.
 11. A monitoring devicefor a distributed antenna system, the monitoring device comprising: aninterface unit configured to receive, from at least one node unit of thedistributed antenna system, report data for a signal passing through aspecific path in a digital part of the unit node through a network; anda controller configured to generate quality information for the signalbased on the report data, wherein the node unit is configured to, at apredetermined period, store data related to the signal being processedby at least one signal processing component on the specific path andtransmit the data to the monitoring device as the report data throughthe network.
 12. The monitoring device of claim 11, wherein the qualityinformation includes a quality index for the signal, wherein the qualityindex is related to at least one signal quality characteristic amongspectrum, power, peak level in time domain, ACLR, EVM, OBW, SEM, NF,CCDF, SNR, and spurious characteristic.
 13. The monitoring device ofclaim 11, wherein the interface unit is further configured to receive,from the node unit, self-analysis information indicative of whether afailure has occurred in the specific path through the network.
 14. Themonitoring device of claim 13, wherein the controller is furtherconfigured to generate a control signal for controlling the signalprocessing component based on the self-analysis information, and whereinthe interface unit is further configured to transmit the control signalto the node unit through the network.